Assessment of Genetic Diversity for Grain Yield and Yield Component Traits in Some Genotypes of Rice ( Oryza Sativa L.)

摘要

Even though there are abundant rice genetic resources, only a fraction is used in breeding programs leading to a narrow genetic base for improved varieties. Increasing the use of available rice germplasm could lead to the development of varieties that are superior in yield and other important agronomic traits. One hundred rice genotypes were used to estimate the genetic variability, heritability, clustering, trait association, and principal components for eight yield and yield-related traits. The experiment was conducted in a 10 × 10 lattice design in three replications under field conditions. The GCV ranged from 4.3% for panicle length to 17.9% for grain yield. Grain yield (GY) had the highest PCV (37.3%), while kernel length had the lowest PCV (7.0%). High heritabilities and moderate genetic advances were observed for days to flowering (DF), plant height (PH), kernel length (KL), and kernel length-to-width ratio (KLW). In general, the magnitudes of genotypic correlations were higher than phenotypic correlations. Grain yield showed a positive association with DF and PL at both genotypic and phenotypic levels, and with PH and KW at the genotypic level only. The genotypes clustered into three groups and the first three principal components explained about 70.3% of the total variation with KLW, KL, DF, and GY being the principal discriminatory characters. There was adequate genetic variability in the germplasm to support breeding for improved grain yield and indirect selection for high yield can be done in early generations using DF, PH, and PL.